After reading Gordon's excellent reviews of the 400D and the three-lense comparison review of lense upgrades, I was "sold" on the 17-55 I-Stabilized (Canon) lense. However, Gordon noted that this was not an L-series lense and of a bit lesser build quality than the L's. THEN, I read the reviews of this lense on Amazon by people who had used it over time, and several reported significant dust issues with it (it apparently isn't weather-sealed like L-series lenses). Does anyone have an opinion about dust with this lense? Are there any weather-proofed, image-stabilized alternative Canon or aftermarket lenses in a similar focal range available? Thanks,

Hi Russ, sadly none of the current EF-S line-up share the same build quality as Canon's L series. The closest focal range to the EF-S 17-55mm in the L series is the 17-40mm f4.0L, although this doesn't have IS. I've used this lens a lot though and it is a particular favourite, depsite some corner softness on my test models when focussed at infinity and zoomed-in.

Then there's the 24-105mm f4.0L which does have IS, but obviously isn't that wide on an APS-C body like the 400D. I think forum member Bob Anderson has one on his though and seems to like it!

Dont get me wrong though, I didn't find any physical fault with the EF-S 17-55 or 17-85mm lenses - they were just not a match for the L series.

I didn't come across any dust or moisture issues with either myself, but obviously it is a concern especially if other owners are reporting it.

Gordon's memory serves him well. I do have the 24-105mm f4.0L lens on my EOS 400D. I don't need the widest angles or the fastest speeds so this lens is my general purpose lens. To be honest it is my only lens apart from the unused kit lens which came with the camera.

I had originally expected to add another lens or two to my collection pretty soon after buying the camera but haven't needed to yet! The only drawback to the lens is its size and weight compared to some but I am more than happy to trade that for the build quality. With the camera easily to hand in a Lowepro Topload Zoom bag attached to my belt I don't notice the weight even on rambles of several hours.

For me the high up front cost of the lens is offset by the fact that I haven't needed to buy another, that the lens should outlast the body and that it won't restrict me to an APS body should I wish to upgrade in the future.

Thanks very much to Gordon and Tom for their responses. They have helped significantly in my camera + lense choice deliberations. I would really prefer the 15-55mm lense because I take a lot of portrait shots, but if dust is going to be an issue, Tom's solution sounds like a good one!